Is it possible to detect iPhone browser agent in .htaccess and redirect the user to the correct iPhone page?
Sure you can -
#redirect mobile browsers
RewriteCond %{HTTP_USER_AGENT} ^.*iPhone.*$
RewriteRule ^(.*)$ http://mobile.yourdomain.com [R=301]
RewriteCond %{HTTP_USER_AGENT} ^.*BlackBerry.*$
RewriteRule ^(.*)$ http://mobile.yourdomain.com [R=301]
RewriteCond %{HTTP_USER_AGENT} ^.*Palm.*$
RewriteRule ^(.*)$ http://mobile.yourdomain.com [R=301]
Taken from here